Such flange sleeves are used, for instance, as a slide bearing for two parts contacting one another and joined by a bolt of a flat pivot joint for doors and hatches, particularly of motor vehicles.
In such flange sleeves, there is always the problem that flowing of the material when the at least one flange is flanged over causing an uneven distribution of thickness over the circumference of the flange. When the material is flanged over, the flange material that is located opposite the butt joint is stretched to the greatest extent, and the material comprising the flange that is directly adjacent the butt joint undergoes only lesser stretching. This process is due to the bending over of the flange in the radial direction and to the increase in circumference of the flange compared to the hollow-cylindrical sleeve portion.
In the region of the butt joint, the result is that the previously closed butt joint is widened into a V-shaped slit. As a result, in the region adjacent to the slit, the flange thickness is greater than in the other regions of the flange. To assure clean, reliable function of a pivot joint, however, it is necessary for the flange to have the same thickness at every point, within certain tolerances.
It is therefore usual for the flange, after being flanged over, to be pressed in order to make the flange thickness uniform. As a result of this reshaping operation, the material flows essentially radially outward, in the region of the flange adjacent to the butt joint or to the V-shaped slit, so that after the pressing operation, the flange no longer has an essentially annular shape. On the contrary, it has a collarlike shape, and in the region of the butt joint, two points or lugs project past the circular arc of the outer diameter.
This adversely affects the properties of the pivot joint.